Color-generating device and display system

ABSTRACT

A light-filtering element for a display device is provided. The element includes at least one filter having a chamber with a filtering fluid, the filtering fluid selectively disposed in an optical path, and a liquid motion actuator selectively configured to move the filtering fluid substantially into and out of the optical path.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 10/251,311 filed on Sep.19, 2002, now U.S. Pat. No. 6,921,175 which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

Various display systems have been used over the years to generateimages. Such display systems may employ image devices, such as cathoderay tubes (CRTs), liquid crystal displays (LCDs), orelectrically-addressed emissive displays, e.g. plasma displays. Thedisplay systems further may incorporate a passive display screen or anactive display screen.

Many of today's display systems include a light source, a color wheel,and a spatial light modulator. Light generated from the light source insuch a display system is directed onto the color wheel, whichsequentially filters light from the light source, typically producingred light, green light, and blue light. The red light, green light, andblue light thus typically are sequentially sent to the spatial lightmodulator, which modulates the colored light depending on the desiredimage. The position of the color wheel therefore often must be trackedsuch that the spatial light modulator appropriately modulates light togenerate an image.

The use of a color wheel may affect the image quality and cost of thedisplay system. For example, the mechanics required to spin the colorwheel typically are large and cumbersome. The use of a color wheel incombination with a spatial light modulator also may result in flickeringand/or sequential color artifacts. These sequential color artifacts mayinclude rainbow-colored shadows that follow rapidly-moving objects invideo images. Moreover, the use of a color wheel may affect the overallbrightness of the image. To overcome the reduction in brightness due tothe color wheel, a high-powered light source may be incorporated withinthe display system. However, high-powered light sources may increase thecost of the display system and may consume a significant amount of powerduring operation. Additionally, fans may be necessary to cool the lightsource. Such fans may increase the noise and overall size of the displaysystem.

SUMMARY OF THE INVENTION

A light-filtering element for a display device is provided. The elementincludes at least one filter having a chamber with a filtering fluid,the filtering fluid selectively disposed in an optical path. The elementfurther includes a liquid motion actuator selectively configured to movethe filtering fluid substantially into and out of the optical path.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a display system having a color generatoraccording to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a display system showing a cut-awaycolor generator including a plurality of color elements, according to anembodiment of the present invention.

FIG. 3 is an isometric view of a color element with multiple colorfilters according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view taken along lines 4-4 in FIG. 3,showing a configuration of color filters in the color element.

FIG. 5 is a cross-sectional view of another color element with multiplecolor filters in accordance with another embodiment of the presentinvention.

FIG. 6 is an isometric view of a color filter of the color element shownin FIG. 5.

FIG. 7 is a schematic illustration of the color filter of FIG. 6 in anon-filtering state.

FIG. 8 is a schematic illustration of a color filter similar to that ofFIG. 7, but with the color filter in a filtering state.

DETAILED DESCRIPTION

Referring initially to FIG. 1, a display system according to anembodiment of the present invention is shown generally at 10. Displaysystem 10 may be any suitable system adapted to display images,including, but not limited to, rear-projection display systems,front-projection display systems, etc.

Display system 10 typically includes a light source, or illuminationsource, 12. Illumination source 12 may be configured to generate light,and to direct light along an optical path 14 toward a screen 16.Illumination source 12 may be any suitable light-generating device,including, but not limited to, a mercury lamp.

Light generated via illumination source 12 may be further directed ontoa color generator, or color-generation device, 18. Color generator 18,as described in more detail below, may include a moveable filteringfluid, such as an absorption medium, that selectively filters light asit passes through the filter. The filtering fluid is typically a liquid,however, any moveable substance may be used, including a gas, a gelatinresin, etc. As discussed below, a liquid motion actuator or promotor,such as a bubble generator or a piezo-element, may be used to move thefiltering fluid. Liquid motion actuator, as used herein, includes anydevice adapted to promote the filtering fluid to move into, and/or outof, the optical path.

Color generator 18 typically is configured to produce color-separatedlight. The color-separated light may be further directed onto a spatiallight modulator 20, such as a micromirror array, digital lightprocessor, or similar device. Spatial light modulator 20, in turn, maybe adapted to modulate incident light to generate an image on screen 16.Both color generator 18 and spatial light modulator 20 may be managed bycontroller 22.

Modulated light from spatial light modulator 20 may be focused andpositioned prior to impinging screen 16. In the exemplary system,spatial light modulator 20 may direct modulated light through projectionoptics 24. Typically, projection optics 24 are configured to focus,size, and position the colored light onto screen 16 to produce an image.Projection optics 24 may include one or more projection lenses.

FIG. 2 schematically illustrates an exemplary display system 26. Displaysystem 26 may be configured to generate a colored image 28 on a screenor display surface 30. In the depicted display system, light source 32is illustrated as a high-pressure mercury lamp, but it need not belimited to such a lamp. As indicated, light source 32 may generate light34, and direct it along an optical path through display system 26. Light34 may be directed through optics 35 (such as a lens or lenses) throughcolor generator 36, and onto spatial light modulator 38.

Color generator 36 may include a plurality of color elements 40configured to filter different wavelengths of light. Each color elementthus may be configured to produce a color that corresponds to theappropriate color of a portion of the image. The color generator may bedigitally controlled, such that each color element selectively filtersout some wavelengths of light, while allowing other wavelengths of lightto pass through. Each color element also may be modulated to affect theintensity of light passing through the color element, as will beunderstood upon reading further.

Colored light, which passes through each color element, may be furtherdirected onto spatial light modulator 38, which is depicted herein as amicromirror array. Each color element may correspond to a mirror, or aplurality of mirrors, within spatial light modulator 38. Colored lightmay be reflected by each mirror in the micromirror array, through optics42, and onto display surface 30 to produce image 28.

In one embodiment, light may be modulated by the display elements so asto accommodate production of various intensities of resultant light.Various shades of gray, for example, may be produced by selectedtime-interleaving of white light (produced where all filters are in thepass-through state) with no light (where all filters are in thefiltering state). Alternatively, or additionally, incident or resultantlight may be modulated by a separate spatial light modulator configuredto selectively disrupt (or pass) white and/or colored light. Eitherarrangement may be configured to produce a full color gamut. FIG. 3illustrates a color element 40 constructed in accordance with oneembodiment of the present invention. As described above, multiple colorelements may form a color generator for a display system. Typically,color element 40 includes a plurality of color filters, or cells, asillustrated at 44, 46, and 48. Color filters may be disposed in theoptical path such that light 49 is directed through the color filters.Each color filter, in turn, may be configured to allow particularwavelengths (colors) of light to pass through, while blocking otherwavelengths (colors) of light. Thus, each color filter may be capable ofdynamically producing a selected color light.

To accomplish the aforementioned filtering, each filter may include afiltering fluid. Typically, the filtering fluid of the filter is adaptedto allow particular colors to pass through the filter, while blockingother colors. For example, the filtering fluid may be a pigmented liquidor dye, including, but not limited to, ink, toner, or other suitablecolor fluid. The filtering fluid also typically is moveable such that itmay be selectively moved to within the optical path of impinging light.

As a non-limiting example, each color element may include a red filter44 having a red-filtering fluid, a green filter 46 having agreen-filtering fluid, and a blue filter 48 having a blue-filteringfluid. When the red-filtering fluid in red filter 44 is in the opticalpath, red light 45 may be passed through the red filter, while othercolor light is blocked. Similarly, when the green-filtering fluid ingreen filter 46 is in the optical path, green light 47 is passed throughthe green filter, while other color light is blocked. Similarly (but notshown), when the blue-filtering fluid in blue filter 48 is in theoptical path, blue light is passed through the blue filter, while othercolor light is blocked. It should be appreciated that other colorfilters may be used, including, but not limited to, cyan filters, yellowfilters, magenta filters, etc. Moreover, although three filters areillustrated, any number of filters may be used.

FIG. 4 further illustrates color element 40, shown in FIG. 3.Specifically, color element 40 includes three color filters, red filter44, green filter 46, and blue filter 48. As discussed above, each colorfilter may include a moveable medium, or filtering fluid, 50, 52, 54.The fluid may be retained within a chamber, typically in the form of awalled structure, as shown. For example, walls 56, and barriers 58, 60,define the chambers in color element 40. As described below, walls 56and barrier 58 are typically constructed of a photo-imageable polymer orother suitable material. Lower barrier 60 is typically a substrate, suchas silicon.

Lower barrier 60, in the exemplary embodiment, serves as the bottom ofthe chambers. Within each chamber, disposed on lower barrier 60 may be aliquid-motion actuator, also referred to in the present illustration asa bubble generator 62. Each bubble generator 62 may be configured toproduce a bubble within the chamber, displacing the fluid from thebottom portion of the chamber. Bubble generators 62 typically take theform of thin film resistors, each adapted to be activated to generate abubble within the corresponding chamber. As shown, multiple thin filmresistors may be packed onto lower barrier 60. In some embodiments,hydrophilic capillaries or other surface features may be disposedadjacent the resistors to draw fluid into the region around theresistors when the resistors are not actuated.

Any excess gas (such as due to a generated bubble) may be releasedthrough an outlet coupled with the chamber. For example, each chamber(shown in FIGS. 3 and 4) include a vent or outlet 63 to reservoir 65,such as a plenum chamber, to accommodate a sudden increase in pressuredue to the boiling of the fluid within the chamber. In some embodiments,oil, or other like substance, may be used to prevent vapor loss fromvents 63. Alternatively, vents 63 may be covered with a flexiblemembrane.

Each chamber may further include a transparent region 64 (indicated bydashed lines) and an opaque region 66 (indicated by dashed, double-dotlines). Light directed onto color element 40 passes through thetransparent region of a filter when the filtering fluid is within thetransparent region. Thus, depending on the state of the color filter andthe position of the filtering fluid, light may or may not pass through acolor filter.

Each color filter may have an actuated (or filtering) state and anon-actuated (or non-filtering) state. In the filtering state, the lightimpinging on the filter may be selectively passed through the filteringfluid, (e.g. colored fluid). Thus, depending on the filtering fluid,some wavelengths (colors) of light may be passed through the filter,while other wavelengths (colors) of light are blocked. Typically, in afiltering state, fluid within the filter is disposed substantiallywithin the transparent region of the filter. In this configuration, aslight passes through the transparent region, it is directed through thefluid, which filters the light to generate a color. In a non-filteringstate, light may be blocked such that little or no light passes throughthe transparent region.

The above color element may be produced by depositing an array of thinfilm resistors onto a transparent substrate. Thereafter, a layer ofdirect imageable material (DIM) may be spun or otherwise disposed ontothe substrate to create a transparent barrier over the resistors, thuscreating bubble chambers. Filtering fluid, such as ink, may then bespread over the transparent surface, filling in the bubble chambers. Thebubble chambers then may be sealed with another transparent layer.Thereafter, light from a light source may be projected onto the colorelement, and by selectively actuating the resistors, bubbles may beproduced in the optical path, thereby selectively blocking the opticalpath.

FIG. 4 illustrates two filters in a filtering state and one filter in anon-filtering state. A filtering state, as used herein, occurs when thefiltering fluid is substantially within the optical path of the light. Anon-filtering state, as used herein, occurs when the filtering fluid issubstantially outside the optical path of the light. It should beappreciated that regardless of state, the filtering fluid typically isnot released from the filter.

Specifically, both filters 44 and 46 are in a filtering state, wherebythe filtering fluid is substantially disposed within transparent region64. Filter 48 is in a non-filtering state, with a bubble 68 disposedwithin transparent region 64. It should be appreciated that, in theexemplary embodiment, transparent region 64 is in the lower portion ofeach chamber (as viewed in FIG. 4), and opaque region 66 is in the upperportion of each chamber (again, as viewed in FIG. 4). Thus, both redfilter 44 and green filter 46 are shown where their respective filteringfluids 50, 52 are in the transparent region.

Accordingly, filtering fluids 50, 52 in filters 44, 46 are in the bottomhalf of the chambers, such that the fluids are within transparent region64. Light impinging on red filter 44 thus passes red light throughfiltering fluid 50. Likewise, light impinging on green filter 46 passesgreen light through filtering fluid 52. Red-filtering fluid 50 thusabsorbs substantially all light except red light. Likewise,green-filtering fluid 52 absorbs substantially all light except greenlight.

In a non-filtering state, the filtering fluid within the filter may besubstantially disposed within opaque region 66, and thus substantiallyoutside of transparent region 64 such that no filtering occurs. Anon-filtering state typically results when bubble generator 62 isactivated. Upon activation, bubble generator 62 may produce a vaporbubble that forces fluid nominally within transparent region 64 to moveinto opaque region 66. In FIG. 4, filter 48 is shown in a non-filteringstate. Specifically, bubble generator 62, associated with blue filter48, may produce a vapor bubble 68. Bubble 68, in turn, has forced bluefluid 54 out of transparent region 64, and into opaque region 66.Accordingly, light directed toward filter 48 impinges bubble 68 andbubble 68 reflects the light such that little or no light passes throughthe blue filter.

Each color filter may dynamically produce at least one color. Thus, whena color filter is in a filtering state, light is filtered through thefiltering fluid to generate a color light. Specifically, red filter 44,when in a filtering state, is configured to produce red light, greenfilter 46, when in a filtering state, is configured to produce greenlight, and blue filter 48, when in a filtering state, is configured toproduce blue light. One or more color filters may be actuated at any onemoment in time. Thus, where all three filters in a color element (redfilter 44, green filter 46, and blue filter 48) are actuated, whitelight may be effectively produced by the color element (where red light,green light and blue light are additive to produce white light).Similarly, by actuating different combinations of filters, differentcolors may be produced. Moreover, having all three filters innon-filtering states may result in a color element that appears dark orblack.

It should be noted that each bubble generator may be activated multipletimes to modulate the emitted light, thereby affecting the intensity ofthe emitted light. For example, a bubble generator may be activatedthousands of times per second.

FIG. 5 illustrates another color element for a color generator accordingto another embodiment of the present invention. As shown in FIG. 5,multiple color filters may be stacked to form a single color element40′. The color filters 70, 74, 78 within color element 40′ may includefiltering fluids of different colors. In the exemplary embodiment, firstcolor filter 70 may include a cyan-filtering fluid 72, second colorfilter 74 may include a magenta-filtering fluid 76, and third colorfilter 78 may include a yellow-filtering fluid 80. The depicted filters,in turn, may be disposed within the optical path of the light sourcesuch that light 82 may pass through the filters sequentially.

As described above, the fluid within each filter may be moveable suchthat the filter may be placed in an actuated (filtering) state or anon-actuated (non-filtering) state. In the filtering state, the fluidtypically is substantially within the optical path such that the lightpasses through the fluid and is filtered. In the non-filtering state,the fluid typically is substantially outside the optical path such thatlight may pass through the filter unfiltered. In contrast to theaforementioned embodiment employing a bubble generator, the filter ofFIG. 5 may employ a vacuum chamber, so as to permit substantiallyunfiltered passage of light through a region from which the filteringfluid has been removed.

Each filter, in turn, typically may be selectively controlled such thatit is independently placed in a filtering state, or a non-filteringstate. To produce color from color element 40′, one or more filterstypically are in filtering states. Thus, when cyan filter 70 is in afiltering state, and magenta filter 74 and yellow filter 78 are innon-filtering states, the light emitted from color element 40′ typicallyis cyan. Similarly, when magenta filter 74 is in a filtering state andthe other filters are in non-filtering states, the light emitted fromcolor element 40′ typically is magenta. Moreover, when yellow filter 78is in a filtering state and the other filters are in non-filteringstates, the light emitted from color element 40′ typically is yellow.

Colors, other than cyan, yellow and magenta may be produced using a cyanfilter, a yellow filter, and/or a magenta filter. For example, if boththe cyan filter and the yellow filter are in filtering states, then thedisplay element may appear green. The green color may result because thecyan filter blocks red light, but passes green light and blue light. Theyellow filter similarly blocks blue light, but passes green light andred light. Since the cyan filter only passes green light and blue light,and the yellow filter only passes green light and red light, the onlycolor to pass through both filters is the green light. Similarly, whenthe yellow filter (which passes green light and red light) and themagenta filter (which passes red light and blue light) are in filteringstates, the display element may appear red. Likewise, when the magentafilter (which passes red light and blue light) and the cyan filter(which passes green light and blue light) are in filtering states, thedisplay element may appear blue. Thus, a single color filter in afiltering state, or any combination of two or more color filters infiltering states, may be used to generate different colors.

It should be appreciated that when all three filters are innon-filtering states, white light may pass directly through the colorelement (as shown in FIG. 5). It further should be appreciated that whenall three filters are in filtering states, color element 40′ may appeardark. For example, if the cyan filter is in a filtering state, the cyanfilter filters out all light except cyan light. Thus, since cyan lightis composed of green light and blue light, both green light and bluelight may pass through. When the yellow filter is in a filtering state,then all light is filtered out except yellow light. Since yellow lightis composed of green light and red light, the green light from the cyanfilter passes through the yellow filter, while the blue light from thecyan filter is blocked. When the magenta filter, which passes red andblue light, is in a filtering state, then the green light from theyellow filter is blocked and no light passes through the final filter,thereby causing the color element to appear dark.

FIG. 6 illustrates one exemplary configuration of a color filter 70.Specifically, color filter 70 includes a fluid chamber 84 configured tocontain a filtering fluid. Fluid chamber 84 may be substantially definedby plates (or side walls) 86, piezo-elements 92, 94, and barriers (orend caps). Although not illustrated, the barriers may seal fluid chamber84 to prevent the fluid from leaking out of the chamber. Plates or sidewalls 86 may be glass, plastic, or other suitable material that permitlight to pass through color filter 70.

Color filter 70 may further include a transparent region 88 and anopaque region 90. Transparent region 88 typically is configured to allowlight to pass through the color filter. Opaque region 90 typically isconfigured to not allow light to pass through. Opaque region 90 mayinclude a mask coupled to plates 86 or within plates 86, so as toprevent light from passing through a portion or portions of the filter.

As described briefly above, each filter has at least two states, anactuated (or filtering state) and a non-actuated (or non-filteringstate). In the filtering state, light may pass through the filter, andthe fluid contained within the filter. Specifically, light 82 passesthrough transparent region 88. In the filtering state, the fluid withina filter is substantially disposed within the transparent region. In thenon-filtering state, the fluid may be disposed in the opaque region 90,allowing light to pass uninterrupted through transparent region 88.

The fluid may be moved between the two regions via a plurality ofmechanisms, including, but not limited to, heat, pressure, etc. In thepresent embodiment, a liquid motion actuator in the form of a pair ofpiezo-elements 92, 94 is employed. The piezo-elements function toselectively push the fluid into the transparent region. Thus, one ormore piezo-elements may be coupled with a fluid chamber. Thepiezo-elements may be selectively deformed to force the fluid from aresting region of the chamber outside the optical path into a selectregion of the chamber within the optical path. As best illustrated inFIGS. 7 and 8, fluid, generally indicated at 96, is contained withinfluid chamber 84. FIG. 7 illustrates a non-filtering state, where fluid96 is substantially outside of transparent region 88 (indicatedschematically by dashed lines). As illustrated, fluid 96 is disposedsubstantially within the opaque region 90 (indicated schematically bydashed, double-dot lines). Thus, light directed through filter 70 maypass through transparent region unobstructed.

A voltage (as schematically illustrated in FIGS. 7 and 8) may be appliedto each piezo-element 92, 94, thereby activating each piezo-element 92,94. When activated, piezo-elements 92 and 94 may deform, squeezing fluid96 from opaque region 90 to transparent region 88. FIG. 8 schematicallyillustrates the effect of activation of piezo-elements 92 and 94. Asillustrated, upon activation piezo-elements 92, 94 constrict the chamberand force the fluid to move into the transparent region. As describedabove, when fluid 96 is disposed within transparent region 88, impinginglight may be filtered as it passes through the fluid. The fluid permitssome wavelengths (colors) of light to pass while blocking otherwavelengths (colors) of light. It should be noted that one, two, three,or more piezo-elements may be used without departing from the scope ofthe invention. Moreover, the piezo-elements may be strips, which alignone or more sides of the chamber. For example, the piezo-elements mayextend around the chamber in a U-shape, a V-shape, etc.

The capillary characteristics of the chamber may be used to promote flowof the fluid within the chamber. For example, any one or more of thesurfaces within chamber 84 may be treated to promote the fluid to returnto the opaque region. For example, the chamber surfaces within theopaque region may be etched to create a hydrophilic surface. Afteractivation of the piezo-element, the fluid may be attracted to theopaque region, due to the surface treatment. Moreover, in addition to,or alternatively, the surfaces of the chamber within the transparentregion may be treated such that they are hydrophobic. Such a treatmentmay promote the fluid to flow out of the transparent region upondeactivation of the piezo-elements.

Although illustrated where actuation of the piezo-elements force thefiltering fluid from the opaque region to the transparent region, itshould be appreciated that the filter may be configured such that thepiezo-elements force the filtering fluid from the transparent region tothe opaque region. Thus, the resting position of the fluid may depend onthe configuration of the filter.

It should be appreciated that the voltage applied to the piezo-elementsmay be finely controlled. By finely controlling the voltage, variousamounts of fluid may be forced into transparent region 88. Thus, aportion of the light may be filtered, while another portion of the lightmay be passed through and unfiltered. Such a configuration allows forgradations in color. For example, a finely controlled yellow filter mayselectively emit very light yellow light, light yellow light, yellowlight, etc.

In some embodiments, multiple liquid motion actuators may be used incombination. For example, a single filter may include both a bubblegenerator and multiple piezo-elements. By controlling each actuator, itmay be possible to selectively modulate the amount of light passingthrough each filter enabling the production of a substantial number ofcolors.

Accordingly, as set forth above, a method for filtering light isprovided. The method includes directing light along an optical path ontoa filter, the filter having filtering fluid moveable into and out of theoptical path, selectively moving the filtering fluid within the filter,and directing light through the filter. Selectively moving the filteringfluid within the filter may include selectively moving the filteringfluid substantially into the optical path. Moreover, directing lightthrough the filter may include passing light through the filtering fluidto produce filtered light. In come embodiments, selectively moving thefiltering fluid may include selectively generating a bubble within theoptical path displacing the filtering fluid to outside the optical path.In such embodiments, directing light through the filter may includereflecting light off the bubble in the optical path. In otherembodiments, selectively moving the filtering fluid may includeselectively actuating at least one piezo-element, which may includedeforming the filter to force the filtering fluid into the optical path.

Moreover, a color generator for a display system having an optical pathis provided. The color generator may include a plurality of colorfilters within the optical path. For example, the color generator mayinclude a first color filter having a first color filtering liquidselectively adapted to filter impinging light, a second color filterhaving a second color filtering liquid selectively adapted to filterimpinging light, and a third color filter having a third color filteringliquid selectively adapted to filter impinging light. The colorgenerator may further include promotion means to move the filteringliquid into and out of the optical path. For example, the colorgenerator may include a first promotion means linked to the first colorfilter to promote motion of the first color filtering liquid into andout of the optical path, a second promotion means linked to the secondcolor filter to promote motion of the second color filtering liquid intoand out of the optical path, and a third promotion means linked to thethird color filter to promote motion of the third color filtering liquidinto and out of the optical path. The color filters may be red, green,blue, cyan, magenta, yellow, or any other color. Additionally, thepromotion means may include a bubble generator and/or a piezo-element.

While various alternative embodiments and arrangements of a method andsystem for generating colored light have been shown and described above,it will be appreciated by those of skill in the art that numerous otherembodiments, arrangements, and modifications are possible and are withinthe scope of the invention. In other words, those skilled in the artwill understand that many variations may be made therein withoutdeparting from the spirit and scope of the invention as defined in thefollowing claims. The description of the invention should be understoodto include all novel and non-obvious combinations of elements describedherein, and claims may be presented in this or a later application toany novel and non-obvious combination of these elements. The foregoingembodiments are illustrative, and no single feature or element isessential to all possible combinations that may be claimed in this or alater application. Where the claims recite “a” or “a first” element orthe equivalent thereof, such claims should be understood to includeincorporation of one or more such elements, neither requiring, norexcluding, two or more such elements.

1. A light-filtering element for a display device, comprising: at leastone filter having a chamber with a filtering fluid, the chamber definingan optical path entering a first side of the chamber and exiting asecond side of the chamber opposite the first side; and a liquid motionactuator selectively configured to move the filtering fluidsubstantially into and out of the optical path by altering the chamberto effect displacement of the filtering fluid within the chamber.
 2. Thelight-filtering element of claim 1, wherein the liquid motion actuatoris configured to selectively alter dimensions of the chamber to displacethe filtering fluid from the optical path.
 3. The light-filteringelement of claim 2, wherein the dimensions of the chamber affectintensity of light passing through the chamber.
 4. The light-filteringelement of claim 1, wherein the filtering fluid is a colored liquid. 5.A color-generating device, comprising: a plurality of color elementsdisposed in an optical path entering a first side of the color elementsand exiting a second side of the color elements opposite the first side,wherein each color element includes at least one filter having a chamberwith a filtering liquid, the filtering liquid being selectively disposedin the optical path; and a liquid motion actuator configured toselectively move the filtering liquid into and out of the optical pathto selectively reflect light in the optical path.
 6. Thecolor-generating device of claim 5, wherein the liquid motion actuatoris configured to selectively alter the chamber to move the filteringliquid into and out of the optical path.
 7. The color-generating deviceof claim 5, wherein the liquid motion actuator is configured to alterthe chamber to selectively move the filtering liquid into and out of theoptical path.
 8. The color-generating device of claim 7, wherein thechamber includes a surface treatment adapted to promote a flow offiltering liquid out of the optical path under direction of the liquidmotion actuator.
 9. A display system, comprising: an illumination sourceconfigured to produce light and direct light along an optical path; acolor generator disposed in the optical path, the color generatorincluding one or more color elements, where one or more color elementshas at least one filter with a color-filtering fluid and an associatedliquid motion actuator, the liquid motion actuator configured toselectively move a substantial volume of the color-filtering liquid byselectively altering the chamber to effect reflection of light toselectively configure the filter in at least one of a filtering stateand a non-filtering state, wherein light directed along the optical pathenters a first side of the filter and exits a second side of the filteropposite the first side; and a display surface configured to receivelight from the color generator to produce a color image.
 10. The displaysystem of claim 9, wherein the at least one filter has a transparentregion disposed in the optical pathway, and where the color-filteringliquid is selectively positionable substantially within the transparentregion when the filter is in a filtering state.
 11. The display systemof claim 9, wherein the at least one filter has a transparent regiondisposed in the optical pathway and where the color-filtering liquid isselectively positionable substantially outside the transparent regionwhen the filter is in the non-filtering state.
 12. The display system ofclaim 9, wherein each color element includes a red filter withred-filtering liquid, a green filter with green-filtering liquid, and ablue filter with a blue-filtering liquid, each filter being separatelyconfigurable in a filtering state and a non-filtering state to producedifferent colored light.
 13. A color element for a display system havinga light source, the color element comprising: a plurality of chambers,each chamber containing a filtering fluid; and an electrically-actuatedelement coupled with each chamber, the electrically-actuated elementbeing configured to selectively alter each chamber to move the filteringfluid between a region of the chamber outside a light path and a regionof the chamber within the light path: wherein the light path enters afirst side of the chamber and exits a second side of the chamberopposite the first side.
 14. The color element of claim 13, wherein thechamber includes a surface treatment adapted to promote a flow of fluidout of the light path under direction of the electrically-actuatedelement.
 15. The color element of claim 13, wherein the region of thechamber within the light path is hydrophobic.
 16. The color element ofclaim 13, wherein the region of the chamber outside the light path ishydrophilic.
 17. A method of filtering light, the method comprising:directing light along an optical path entering a first side of a filterand exiting a second side of the filter opposite the first side, thefilter having filtering liquid moveable into and out of the opticalpath; selectively moving the filtering fluid within the filter byaltering dimensions of the filter; and directing light through thefilter.
 18. The method of claim 17, wherein selectively moving thefiltering liquid within the filter includes selectively moving thefiltering liquid substantially into the optical path, and directinglight through the filter includes passing light through the filteringliquid to produce filtered light.
 19. The method of claim 17, whereinselectively altering dimensions of the filter includes actuating atleast one electrically-actuated element to deform the filter, andthereby, to force the filtering liquid into the optical path.
 20. Themethod of claim 19, wherein directing the light through the filterincludes passing the light through the filtering liquid to produce acolor.
 21. A light-filtering element for a display device, comprising:at least one filter having a chamber with a filtering fluid, the chamberdefining an optical path entering a first side of the chamber andexiting a second side of the chamber opposite the first side; and aliquid motion actuator selectively configured to move the filteringfluid substantially into and out of the optical path and by selectivelyaltering the dimensions of the chamber.
 22. The light-filtering elementof claim 21, wherein the dimensions of the chamber affect intensity oflight passing through the chamber.
 23. A color-generating device,comprising: a plurality of color elements disposed in an optical pathentering a first side of the color elements and exiting a second side ofthe color elements opposite the first side, wherein each color elementincludes at least one filter having a chamber with a filtering liquid,the filtering liquid being selectively disposed in the optical path; anda liquid motion actuator configured to selectively move the filteringliquid into and out of the optical path by selectively altering thechamber.
 24. A color-generating device, comprising: a plurality of colorelements disposed in an optical path entering a first side of the colorelements and exiting a second side of the color elements opposite thefirst side, wherein each color element includes at least one filterhaving a chamber with a filtering liquid, the filtering liquid beingselectively disposed in the optical path; and a liquid motion actuatorconfigured to selectively move the filtering liquid into and out of theoptical path by altering the chamber.
 25. The color-generating device ofclaim 24, wherein the chamber includes a surface treatment adapted topromote a flow of filtering liquid out of the optical path underdirection of the liquid motion actuator.